Automatic graphitization system for radiocarbon analysis by accelerator mass spectrometry

• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465681805

An automatic graphitization system is required for performing radiocarbon analyzes (14C) using accelerator mass spectrometry (AMS). The graphitization system converts carbon contained in organic and inorganic samples (e.g., sediment, plants, bones, mussels, water) into carbon dioxide by combusting organic samples or by hydrolyzing inorganic samples with acid. The carbon dioxide is then transferred by a helium stream to a molecular sieve. By heating the molecular sieve material, the carbon dioxide is released into so-called reactors, where it is reduced to elemental carbon after adding hydrogen and by applying heat. The 14C concentration is then determined in the AMS.The advantage of the system is that it is operated fully automatically, which means that a high sample throughput is possible. In addition, no liquid nitrogen is required to concentrate the carbon dioxide as with alternative methods. With the system applied for, all types of samples that are to be processed in ongoing and planned projects can be processed. This is currently not the case.Age determinations are important for answering geoscientific, archaeological, art historical and other questions. 14C analysis also provides information about carbon cycle processes such as conversion rates of carbon or proportions of different carbon sources and their age and/or origin, which is used in ongoing research projects on carbon release from thawing, arctic permafrost soils. In addition, 14C analyzes are an important method in the two ongoing CRC's 806 and 1211 at the University of Cologne and should also be used in the ongoing and planned projects given below.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Automatisches Graphitisiersystem für Radiokohlenstoffanalysen mit Beschleuniger-Massenspektrometrie
• Instrumentation Group: 1700 Massenspektrometer
• Applicant Institution: Universität zu Köln
• Leader: Professorin Dr. Janet Rethemeyer